Unit 203 - Transmission

Transmission Voltages

The power station generates a supply of 23kV. This supply is stepped up to 400kV via a transformer for transmission over long distances. 275kV transmission voltages are also common.

A grid supply point transformer steps the transmission voltage down to a distribution voltage of 132kV at 14 regional distribution network operators (DNO) across the nation.

The 132kV distribution does not generally enter towns and cities because the switchgear and transformers cover a large area. They are therefore outside towns and a lower 33kV is supplied to a city.

In the countryside the 33kV supply is distributed via wooden pylons but in urban areas they can be transmitted via underground cables.

Generator transformer

23kV to 400kV

275kV Transmission line

11kV Distribution line

400V Distribution line

Grid supply point transformer

275kV/400kV to 132kV for distribution

132kV Distribution line with wood pylon